<%= label :state, 'State' %><br />

<%= collection_select(:city, :state_id, @states, :id, :name, :prompt =>true) %>

<%# if !@states.nil? %>
  <%#= select_tag 'state', '<option value="-1"selected="selected">Seleccionar</option>' +
      collection_select(:city, :state_id, @states, :id, :name)%>
  
<%# else %>
  <%#= select_tag 'state', '<option value="-1"selected="selected">Seleccione estado</option>' %>
<%# end %>